title: Pegylated interferon-α2b and ribavirin decrease claudin-1 and E-cadherin expression in HepG2 and Huh-7.5 cells.
abstract: BACKGROUND
  Hepatitis C virus (HCV) infection usually results in long-term viremia. Entry of HCV into the hepatocyte requires claudin-1, -6, -9 and occludin. The efficacy of Pegylated interferon-α (PEG-IFN) treatment against HCV infection increased when ribavirin (RBV) was added to the therapeutic scheme. Our aim was to investigate if PEG-IFN plus RBV regulate claudin expression.
  
  
  METHODS
  HepG2, Huh-7 and Huh-7.5 cells were treated with PEG-IFN-α2a or α2b and/or RBV at different times before obtaining the cytosolic, membrane and cytoskeletal fractions. Claudin-1, 3, 4, 6, and 9, E-cadherin and occludin expression was evaluated by Western blot analysis. Transepithelial electrical resistance (TER) was also determined.
  
  
  RESULTS
  Claudin-1, 3, 4, 6, E-cadherin and occludin are constitutively expressed mainly in HepG2 cell membrane. Claudin-1 and E-cadherin cell membrane expression diminished after exposure to PEGIFNα2b (50 ng) + RBV(50 μg); the maximal decrease was observed with 200 ng of PEG-IFNα2b + 200 μg of RBV. The effect was less intense with PEG-IFNα2a. The inhibition of claudin-1 and E-cadherin expression in Huh-7 and Huh-7.5 cells was only observed with 200 ng of PEG-IFNα2b + 200 μg of RBV. TER diminished marginally in the HCV containing hepatoma cells with 200 ng of PEG-IFNα2b + 200 μg of RBV. Claudin-1 mRNA expression level was not affected by the combined treatment.
  
  
  CONCLUSIONS
  The increased therapeutic efficacy of the PEG-IFNα2b plus RBV treatment could be secondary to the inhibition of claudin-1 and E-cadherin cell membrane expression.
authors.affiliation: Departamento de Biología Celular y Tisular, Facultad de Medicina, UNAM, México, D.F. 04510, México. erendon@bq.unam.mx
authors.forename: Erika P
authors.initials: EP
authors.lastname: Rendón-Huerta
authors.forename: Ana
authors.initials: A
authors.lastname: Torres-Martínez
authors.forename: Claudia
authors.initials: C
authors.lastname: Charles-Niño
authors.forename: Ana M
authors.initials: AM
authors.lastname: Rivas-Estilla
authors.forename: A
authors.initials: A
authors.lastname: Paez
authors.forename: Teresa I
authors.initials: TI
authors.lastname: Fortoul
authors.forename: Luis F
authors.initials: LF
authors.lastname: Montaño
mesh_terms: D015703:Antigens, CD; D000998:Antiviral Agents / Q000494:pharmacology*; D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D062445:Claudin-1 / Q000378:metabolism*; D015536:Down-Regulation; D017097:Electric Impedance; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D012254:Ribavirin / Q000494:pharmacology*; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
chemical_list: D015703:Antigens, CD; D000998:Antiviral Agents; C513384:CDH1 protein, human; C568108:CLDN1 protein, human; D015820:Cadherins; D062445:Claudin-1; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012333:RNA, Messenger; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C417083:peginterferon alfa-2b